232 PRACTICAL ORGANIC CHEMISTRY with ammonia and the liquid concentrated on the water-bath until crystals of quinine sulphate begin to form on the surface*. The liquid is allowed to cool and filtered. A further quantity of crystals may be obtained from the mother-liquor by evaporation, but the product is not so pure. The crystals arc purified by recrystallisation from water. Yield, i to 2 grams, or more, according" to the quality of the bark. Properties.—The free base, which is precipitated with sodium carbonate from a solution of its salts, crystallises with 31•!.,<). The anhydrous base melts at 277° ; soluble in alcohol and el her, Reactions,— Use a solution of the hydrochloride prepared by adding a few drops of hydrochloric acid to the sulphate mixed with water. 1. Add to a little of the solution a few drops of iodine solu- tion ; a brown amorphous precipitate is formed. This reaction is given by many of the alkaloids. 2. Acid chlorine water and then ammonia in excess. An emerald green colouration is produced. 3. Add sodium carbonate solution and then shake with etlu.r. The free base is precipitated and dissolves in the ether. Decani the ether on to a watch-glass and let it evaporate. Crystals ot the base remain. 4. Dissolve in a few drops of acetic acid and .add a Iar;,;e volume of water. A blue fluorescent liquid is obtained. See Appendix, p. 319. PREPARATION r 14. /N Diazobeiizolimide, C(,H-N' i; \N Phenylmethyltriazole carboxylic Acid, N.C.H, N /\ ' \ r I N/ CCII ;i C.COOH Dim roth, Her., 1902, 35, 1,029. 30 grms. phenylhydrazine. 45 c.c. cone, hydrochloric acid (in 400 c.c. water). 24 grms. sodium nitrite (in 50 c.c. water).